(TRENTON) – An additional tree infested with the invasive pest, Asian longhorned beetle (ALB), has been found in the City of Linden, Union County, creating the need to expand the existing ALB quarantine zone in that area, Secretary of Agriculture Charles M. Kuperus said today.

The quarantine zone will now be extended into parts of two new municipalities, Roselle Borough and the City of Elizabeth. The existing zone encompasses the towns of Linden, Rahway, Carteret and Woodbridge.

The infested horsechestnut tree found on March 23 in the northern section of Linden was the first new detection since November 2005. It was removed on Wednesday, March 29. The tree had approximately 20 fresh egg sites on it, but no exit holes, indicating that no adult beetles had emerged from the tree.

“This is part of our continuing cooperative work with the USDA and other agencies in making sure that we eradicate this invasive pest from New Jersey,” said Secretary Kuperus. “As we continue surveying the infestation area, we may from time to time find an additional infested tree, and that may call for more surveying in other areas. Members of the team working on this eradication have already met with Elizabeth and Roselle Borough officials to outline the survey and treatment work that will occur shortly in those communities. We look forward to a cooperative relationship with them.”

Work in the two new municipalities will consist of both ground and tree-climbing surveys to determine if any additional infested trees exist within a 1 ¼ -mile radius of the one found in northern Linden. Some high-risk host trees also will be treated with imidacloprid, an insecticide that can prevent the beetle from infesting a tree. However, once a tree is infested and the beetle larvae burrow into the hardwood, insecticides are ineffective and the tree must be taken down.

The beetle is an invasive pest native to China and Korea that destroys a variety of trees, primarily maples, but also elms, horsechestnuts and others, by burrowing through the hardwood and essentially killing the tree from the inside out. It was first discovered in the United States in Brooklyn and is believed to have entered the country in untreated wood packing materials.

The beetle first appeared in New Jersey in Jersey City in 2002. Removal of 113 infested and 348 high-risk host trees in that quarantine zone has proven successful as no further finds of the beetle have occurred there after three years of surveying. A second infestation was found in August 2004 in Carteret, Woodbridge, Rahway and Linden. Tree removal efforts and additional survey work have been ongoing there since that find.

As of March 29, crews have removed 528 infested trees, including the one new find, and 15,663 high-risk host trees in that infestation. The Department of Agriculture (NJDA) has worked cooperatively with the United States Department of Agriculture (USDA) in the survey and removal work in both infestation areas. In both areas, the NJDA has worked with the Department of Environmental Protection and the U.S. Forestry Service to replace trees in residential areas and parks. To date, 433 trees have been replaced in the Jersey City infestation area and 2,112 have been replaced in the Middlesex/Union infestation area. The replacement trees are all species that the ALB will not infest.